CN105142260A

CN105142260A - LED driving circuit applicable to silicon controlled rectifier light modulator, and control circuit thereof

Info

Publication number: CN105142260A
Application number: CN201410393364.0A
Authority: CN
Inventors: 谢小高; 叶美盼; 蔡拥军
Original assignee: Hangzhou Silan Microelectronics Co Ltd
Current assignee: Hangzhou Silan Microelectronics Co Ltd
Priority date: 2014-08-12
Filing date: 2014-08-12
Publication date: 2015-12-09
Anticipated expiration: 2034-08-12
Also published as: CN105142260B

Abstract

The invention provides an LED driving circuit applicable to a silicon controlled rectifier light modulator, and a control circuit thereof. The control circuit comprises a light modulation phase detection circuit, a phase filtering circuit connected with the light modulation phase detection circuit, a non-linear reference circuit connected with the phase filtering circuit, a zero cross detection circuit in direct or indirect coupling with an output end of the LED driving circuit, an output current simulation circuit connected with the zero cross detection circuit, an average current ring adjusting circuit connected with the non-linear reference circuit and the output current simulation circuit, a reset circuit connected with the average current ring adjusting circuit, an interrupted time-delay circuit connected with the phase filtering circuit, and a main driving circuit connected with the reset circuit, the interrupted time-delay circuit and the zero cross detection circuit. The control circuit can realize high power factor single-stage light modulation and has advantages of no scintillation and good compatibility.

Description

Be applicable to LED drive circuit and the control circuit thereof of controllable silicon dimmer

Technical field

The present invention relates to LED Driving technique, particularly relate to a kind of LED drive circuit and the control circuit thereof that are applicable to controllable silicon dimmer.

Background technology

Compare with conventional lamp sources such as fluorescent lamps with incandescent lamp, the advantages such as LED has efficiently, good directivity, good stability, reliability are high, the life-span is long, are therefore widely used in each place.And one of light-dimming method that controllable silicon light modulation method is current LED to be most widely used, it is widely used in the field such as stage illumination, lighting and ambient lighting.And well-known, due to the characteristic of controllable silicon dimmer, it needs certain maintenance electric current guarantee conducting, so cannot directly be connected on the live wire of LED driver, just needs LED drive circuit to do corresponding change.

In prior art, common solution carries out two-stage light modulation: namely the first order adopts booster circuit, for storage power, and detects the light modulation angle exchanging input; The second level adopts reduction voltage circuit, exports this output current corresponding to light modulation angle.In addition, in order to the LED driver met not with dimmer also has the requirement of High Power Factor, control circuit must realize power factor emendation function.

But the mode cost of two-stage light modulation is higher, therefore, simple, the high performance single-stage dimming driving circuit of research structure and its control circuit are a job very with actual application value.

Summary of the invention

The problem to be solved in the present invention is to provide a kind of LED drive circuit and the control circuit thereof that are applicable to controllable silicon dimmer, can realize the light modulation of High Power Factor single-stage, has the features such as power factor, high flicker free and compatibility are good.

For solving the problems of the technologies described above, the invention provides a kind of control circuit being applicable to the LED drive circuit of controllable silicon dimmer, comprising:

For detecting the light modulation phase detecting circuit of the angle of flow of alternating current source after controllable silicon dimmer, by through controllable silicon dimmer cut and the half-sinusoid signal produced after rectifier bridge rectification is converted to square-wave signal;

Be connected with described light modulation phase detecting circuit, be filtered into by described square-wave signal the phase filtering circuit of direct current average voltage;

Be connected with described phase filtering circuit, produce according to the size of described direct current average voltage the non-linear reference circuit of corresponding reference voltage, and the reference voltage that described non-linear reference circuit produces raises with the rising of described direct current average voltage;

Be coupled with the output of described LED drive circuit, detect the current zero-crossing point of output diode of this LED drive circuit and the zero cross detection circuit of ON time directly or indirectly;

The output current analog circuit of the sampled voltage analog output current be connected with described zero cross detection circuit, exported according to Output rusults and the described LED drive circuit of this zero cross detection circuit;

Be connected with output current analog circuit with described non-linear reference circuit, produce according to the output signal of described reference voltage and described output current analog circuit the average current ring regulating circuit adjusting voltage signal;

Be connected with described average current ring regulating circuit, produce according to the size of described adjustment voltage signal the reset circuit of switching tube ON time;

Be connected with described phase filtering circuit, according to the interrupted delay circuit of the size adjustment interrupting time of described direct current average voltage, described interrupting time shortens along with the rising of described direct current average voltage;

With described reset circuit, interrupted delay circuit and zero cross detection circuit is connected, produce the main drive circuit of control signal according to the output signal of described switching tube ON time and interrupting time and zero cross detection circuit, described control signal is in order to control the turn-on and turn-off of the switching tube of described LED drive circuit.

According to one embodiment of present invention, described light modulation phase detecting circuit comprises:

Potential-divider network, its first input end receives the half-sinusoid signal of described cut, its second input end grounding;

4th electric capacity, its first end connects the output of described potential-divider network, its second end ground connection;

First comparator, its first input end connects the output of described potential-divider network, and its second input receives the first reference voltage preset, and its output is as the output of described light modulation phase detecting circuit.

According to one embodiment of present invention, described phase filtering circuit comprises:

9th resistance, its first end connects the output of described light modulation phase detecting circuit, and its second end is as the output of described phase filtering circuit;

5th electric capacity, its first end connects the second end of described 9th resistance, its second end ground connection.

According to one embodiment of present invention, described non-linear reference circuit comprises:

Second comparator, its first input end receives the sawtooth signal preset, and its second input connects the output of described phase filtering circuit;

14 resistance, its first end connects the output of described second comparator;

7th electric capacity, its first end connects the second end of described 14 resistance, its second end ground connection.

Second comparator, its first input end receives the exponential wave signal preset, and its second input connects the output of described phase filtering circuit;

According to one embodiment of present invention, described zero cross detection circuit comprises: the 3rd comparator, its first input end ground connection, its second input is coupled with the output of described LED drive circuit directly or indirectly, and its output is as the output of described zero cross detection circuit.

According to one embodiment of present invention, described output current analog circuit comprises:

3rd rest-set flip-flop, its RESET input connects the output of described zero cross detection circuit, and its set input connects the output of described reset circuit, and its reversed-phase output produces the first switching signal;

8th switch, its first end receives described sampled voltage, and its control end connects the reversed-phase output of described 3rd rest-set flip-flop to receive described first switching signal;

16 resistance, its first end connects the second end of described 8th switch, and its second end is as the output of described output current analog circuit;

9th switch, its first end connects the second end of described 16 resistance, its second end ground connection, and its control end connects the reversed-phase output of described 3rd rest-set flip-flop to receive described first switching signal;

Tenth electric capacity, its first end connects the second end of described 8th switch, its second end ground connection.

9th switch, its first end connects the second end of described 16 resistance, and its second end is via the 17 grounding through resistance, and its control end connects the positive output end of described 3rd rest-set flip-flop;

According to one embodiment of present invention, described average current ring regulating circuit comprises:

Second operational amplifier, its first input end connects the output of described non-linear reference circuit, and its output is as the output of described average current ring regulating circuit;

15 resistance, its first end connects the second input of described second operational amplifier, and its second end connects the output of described output current analog circuit;

8th electric capacity, its first end connects the second input of described second operational amplifier, and its second end connects the output of described second operational amplifier.

According to one embodiment of present invention, described reset circuit comprises:

6th comparator, its second input connects the output of described average current ring regulating circuit, and its output is as the output of described reset circuit;

Second current source, its first end connects the first input end of described 6th comparator, its second end ground connection;

9th electric capacity, its first end connects the first input end of described 6th comparator, its second end ground connection;

7th switch, its first end connects the first input end of described 6th comparator, and its second end ground connection, its control end receives the inversion signal of described control signal.

According to one embodiment of present invention, described interrupted delay circuit comprises:

Tenth resistance, its first end connects the output of described phase filtering circuit;

First operational amplifier, its second input connects the second end of described tenth resistance, and its second input also connects the output of described first operational amplifier via the 11 resistance;

12 resistance, its first end receives the second reference voltage preset, and its second end connects the first input end of described first operational amplifier;

13 resistance, its first end connects the first input end of described first operational amplifier, its second end ground connection;

5th comparator, its second input connects the output of described first operational amplifier;

First current source, its first end connects the first input end of described 5th comparator, its second end ground connection;

6th electric capacity, its first end connects the first input end of described 5th comparator, its second end ground connection;

4th rest-set flip-flop, its RESET input receives described control signal, and its set input connects the output of described zero cross detection circuit, and its reversed-phase output produces second switch signal;

6th switch, its first end connects the first input end of described 5th comparator, and its second end ground connection, its control end receives described second switch signal.

According to one embodiment of present invention, described main drive circuit comprises:

With door, its first input end connects the output of described zero cross detection circuit, and its second input connects the output of described interrupted delay circuit;

Second rest-set flip-flop, its set input connects output that is described and door, and its RESET input connects the output of described reset circuit, and its positive output end produces described control signal;

Drive amplification circuit, its input connects the positive output end of described second rest-set flip-flop to amplify the driving force of described control signal.

For solving the problems of the technologies described above, present invention also offers a kind of LED drive circuit being applicable to controllable silicon dimmer, comprising:

Controllable silicon dimmer, its input connects the first end of alternating current source;

Rectifier bridge, its first input end connects the output of described controllable silicon dimmer, and the second input connects the second end of described alternating current source;

Input filter circuit, its first input end connects the first output of described rectifier bridge, its second input end grounding, and described input filter circuit is used for filtering high frequency ripple; Second output head grounding of described rectifier bridge;

Control circuit described in above-mentioned any one, its first input end connects the first output of described rectifier bridge;

LED driver, its input connects the output of described input filter circuit, and its first output connects the second input of described control circuit, and described LED driver is used for providing energy to load;

Switching tube, its first end connects the second output of described LED driver, and its second end connects the 3rd input of described control circuit and via sampling resistor ground connection, its control end receives the control signal that described control circuit produces;

Output capacitance, its first end connects the 3rd output of described LED driver, and its second end connects the 4th output of described LED driver.

According to one embodiment of present invention, this LED drive circuit also comprises: the first antihunt circuit, its first end connects the first input end of described rectifier bridge, its second end connects the second input of described rectifier bridge, and described first antihunt circuit triggers the vibration of the AC input current of moment for limiting described controllable silicon dimmer.

According to one embodiment of present invention, described first antihunt circuit comprises:

First resistance, its first end connects the output of described controllable silicon dimmer;

First electric capacity, its first end connects the second end of described first resistance, and its second end connects the second end of described alternating current source.

According to one embodiment of present invention, described LED drive circuit also comprises: the first antihunt circuit, its first end connects the first output of described rectifier bridge, its second end connects the second output of described rectifier bridge, and described first antihunt circuit triggers the vibration of the AC input current of moment for limiting described controllable silicon dimmer.

First resistance, its first end connects the first output of described rectifier bridge;

First electric capacity, its first end connects the second end of described first resistance, and its second end connects the second output of described rectifier bridge.

According to one embodiment of present invention, described LED drive circuit also comprises: the second antihunt circuit, second output of described rectifier bridge is via this second antihunt circuit ground connection, and described second antihunt circuit triggers the peak overshoot of the input current of moment for reducing described controllable silicon dimmer.

According to one embodiment of present invention, described second antihunt circuit comprises:

Second resistance, its first end connects the first output of described rectifier bridge;

3rd resistance, its first end connects the second end of described second resistance, and its second end connects the second output of described rectifier bridge;

First diode, its anode connects the first end of described 3rd resistance;

Triode, its base stage connects the anode of described first diode, and its emitter connects the negative electrode of described first diode, and its collector electrode connects the second end of described 3rd resistance;

Voltage-stabiliser tube, its negative electrode connects the negative electrode of described first diode, and its anode connects the second end of described 3rd resistance;

Second electric capacity, its first end connects the negative electrode of described first diode, and its second end connects the second end of described 3rd resistance;

3rd switching tube, its control end connects the first end of described second electric capacity, and its first end connects the second end of described second electric capacity, its second end ground connection;

4th resistance, its first end connects the second end of described 3rd resistance, its second end ground connection.

According to one embodiment of present invention, described LED drive circuit also comprises: leadage circuit, and the first output of described rectifier bridge is via this leadage circuit ground connection, and described leadage circuit is for compensating the maintenance electric current of described controllable silicon dimmer at dimming cycle.

According to one embodiment of present invention, described control circuit also comprises dummy load drive circuit, size according to the direct current average voltage of described phase filtering circuit generation controls described leadage circuit, described dimmer conduction angle is larger, then described direct current average voltage is higher, then the dummy load electric current that provides of described leadage circuit is less.

According to one embodiment of present invention, described leadage circuit comprises:

5th resistance, its first end connects the first output of described rectifier bridge;

Tenth switching tube, its first end connects the second end of described 5th resistance;

18 resistance, its first end connects the control end of described tenth switching tube, and its second end connects the output of described dummy load drive circuit;

6th resistance, its first end connects the second end of described tenth switching tube, its second end ground connection.

According to one embodiment of present invention, described dummy load drive circuit comprises:

Sawtooth waveforms maker, for generating the sawtooth waveforms with predeterminated frequency and peak value and valley;

4th comparator, its first input end receives described sawtooth waveforms, and its second input connects the output of described phase filtering circuit;

NPN triode, its base stage connects the output of described 4th comparator, and its collector electrode receives the direct voltage preset;

PNP triode, its base stage connects the output of described 4th comparator, and its emitter connects the emitter of described NPN triode, its grounded collector.

According to one embodiment of present invention, described input filter circuit comprises:

3rd diode, its anode connects the first output of described rectifier bridge;

3rd electric capacity, its first end connects the negative electrode of described 3rd diode, its second end ground connection.

3rd diode, its anode connects the first output of described rectifier bridge;

3rd electric capacity, its first end connects the negative electrode of described 3rd diode;

First filtered diode, its negative electrode connects the second end of described 3rd electric capacity, its plus earth;

Second filtered diode, its anode connects the second end of described 3rd electric capacity;

3rd filtered diode, its negative electrode connects the first end of described 3rd electric capacity, and its anode connects the negative electrode of described second filtered diode;

Filter capacitor, its first end connects the anode of described 3rd filtered diode, its second end ground connection.

According to one embodiment of present invention, described input filter circuit comprises: the 3rd electric capacity, and its first end connects the first output of described rectifier bridge, its second end ground connection.

According to one embodiment of present invention, described LED driver comprises:

Transformer, the different name end of its former limit winding connects the output of described input filter circuit, the Same Name of Ends of its former limit winding connects the first end of described switching tube, the different name end of its vice-side winding connects the second end of described output capacitance, the Same Name of Ends of its auxiliary winding connects the second input of described control circuit, the different name end ground connection of its auxiliary winding;

Output diode, its anode connects the Same Name of Ends of the vice-side winding of described transformer, and its negative electrode connects the first end of described output capacitance.

According to one embodiment of present invention, described LED driver also comprises: uptake pathway, with the former limit winding parallel of described transformer.

Inductance, its different name end connects the output of described input filter circuit, and its Same Name of Ends connects the first end of described switching tube;

With the auxiliary winding of described inductance coupling high, its Same Name of Ends connects the second input of described control circuit, its different name end ground connection;

Output diode, its anode connects the Same Name of Ends of described inductance, and its negative electrode connects the second end of described output capacitance.

Inductance, its different name end connects the output of described input filter circuit, and its Same Name of Ends connects the first end of described output capacitance;

Output diode, its anode connects the first end of described switching tube, and its negative electrode connects the first end of described inductance.

Compared with prior art, the present invention has following characteristics:

The LED drive circuit of the embodiment of the present invention makes the input current overshoot of controllable silicon dimmer conducting moment little by the first antihunt circuit and the second antihunt circuit and weakens the vibration of input current, makes input voltage excessively arrive the sinusoidal waveform of normal cut smoothly; By leadage circuit, make controllable silicon dimmer have enough maintenance electric currents, ensure that the sine wave of input cut does not suddenly change; By light modulation phase detecting circuit, the sine wave of cut is converted to corresponding square wave, and signal transmission to phase filtering circuit; By phase filtering circuit, square-wave voltage is filtered into direct current average voltage; By non-linear reference circuit, according to the output voltage size of phase filtering circuit, produce corresponding different output current benchmark, if phase filtering circuit output voltage is higher, then the reference voltage of non-linear reference circuit output is higher, and LED output current is larger; By dummy load drive circuit, according to phase filtering circuit output voltage size, if dimmer conduction angle is larger, then phase filtering circuit output voltage is higher, then correspondingly the duty ratio of dummy load drive circuit output square wave is lower, and the dummy load electric current that leadage circuit provides is less; By interrupted delay circuit, according to phase filtering circuit output voltage size adjustment system interrupting time, if phase filtering circuit output voltage is higher, then system interrupting time is shorter, thus avoids the problem that the system frequency work when controllable silicon cut angle is larger is too high, input and output energy is not easy balance; By output current analog circuit, simulate the signal of output current, deliver to average current ring regulating circuit; Average current ring regulating circuit, according to the output of the output of non-linear benchmark and output current analog circuit, exports the voltage signal of an adjustment, to reset circuit; Reset circuit, according to the output voltage size of average current ring regulating circuit, produces the ON time of corresponding switching tube; Main drive circuit produces a control signal according to the output of reset circuit, the interrupted output of delay circuit and the output of zero cross detection circuit, pass to the control end of main circuit switch pipe, thus LED drive circuit is normally worked, and make the switching tube of LED drive circuit be operated in Valley-Switching pattern (quasi-resonant mode) by zero cross detection circuit, thus reduce switching loss.

Beneficial effect of the present invention is:

(1) adopt the LED drive circuit embodiment of control circuit of the present invention can realize the single-stage light modulation of LED drive circuit, compare two-stage light adjusting circuit, cost is lower, and has power factor high;

(2) control circuit of the present invention adopts non-linear reference circuit, dimming scope is broadened, simultaneously in conjunction with output current analog circuit and average current loop regulation circuit, indirectly achieve the current constant control to output current, be with controllable silicon dimmer and when not being with controllable silicon dimmer, all there is good line regulation;

(3) adopt in the LED drive circuit embodiment of control circuit of the present invention, the size of the maintenance electric current that control circuit can regulate leadage circuit to provide, is conducive to raising the efficiency, and can realize flicker free, level and smooth light modulation, the compatible advantage such as good;

(4) switching tube of control circuit control LED drive circuit of the present invention is operated in Valley-Switching pattern (quasi-resonant mode), thus reduces switching loss, and drive efficiency is high.

Accompanying drawing explanation

Fig. 1 is the general structure block diagram of the LED drive circuit of the embodiment of the present invention;

Fig. 2 is the detailed block diagram of the LED drive circuit of the embodiment of the present invention;

Fig. 3 is the detailed circuit diagram of the first example of the LED drive circuit of the embodiment of the present invention;

Fig. 4 a shows the another kind of realizing circuit of the input filter circuit in the LED drive circuit of the embodiment of the present invention;

Fig. 4 b shows another realizing circuit of the input filter circuit in the LED drive circuit of the embodiment of the present invention;

Fig. 5 is the signal waveform schematic diagram of LED drive circuit shown in Fig. 3;

Fig. 6 shows the detailed circuit diagram of the second example of the LED drive circuit of the embodiment of the present invention;

Fig. 7 shows the detailed circuit diagram of the 3rd example of the LED drive circuit of the embodiment of the present invention.

Embodiment

Below in conjunction with specific embodiments and the drawings, the invention will be further described, but should not limit the scope of the invention with this.

With reference to figure 1, the LED drive circuit being applicable to controllable silicon dimmer of the present embodiment comprises: controllable silicon dimmer TR1, rectifier bridge B1, the first antihunt circuit 100, second antihunt circuit 200, leadage circuit 300, input filter circuit 400, LED driver 500, control circuit 1600, switching tube Q1, sampling resistor Rs and output capacitance Co.

With reference to figure 2, control circuit 1600 can comprise: light modulation phase detecting circuit 600, phase filtering circuit 700, dummy load drive circuit 800, non-linear reference circuit 900, average current ring regulating circuit 1000, reset circuit 1100, interrupted delay circuit 1200, output current analog circuit 1300, zero cross detection circuit 1400 and main drive circuit 1500.

Composition graphs 1 and Fig. 2, the input of controllable silicon dimmer TR1 connects first output of alternating current source AC, and the output of controllable silicon dimmer TR1 connects the first input end of rectifier bridge B1; First antihunt circuit 100 is connected in parallel between the output of controllable silicon dimmer TR1 and second output of alternating current source AC; Second output of the second input termination alternating current source AC of rectifier bridge B1; Second antihunt circuit 200 is connected between second output of rectifier bridge B1 and ground; First output of the first termination rectifier bridge B1 of leadage circuit 300, the second end ground connection; First output of the input termination rectifier bridge B1 of input filter circuit 400, exports the input of termination LED driver 500; The first end of LED driver 500 second output switching tube Q1, the first end of the second termination sampling resistor Rs of switching tube Q1, the second end ground connection of sampling resistor Rs; Output capacitance Co is connected in parallel between the 3rd output of LED driver 500 and the 4th output.

The input of light modulation phase angle detection circuit 600 connects first output of rectifier bridge B1, the input of phase filtering circuit 700 connects the output of light modulation phase detecting circuit 600, the output of the input termination phase filtering circuit 700 of dummy load drive circuit 800, the output of the input termination phase filtering circuit 700 of non-linear reference circuit 900, the output of the input termination phase filtering circuit 700 of interrupted delay circuit 1200, first output of the input termination LED driver 500 of zero cross detection circuit 1400, two inputs of output current analog circuit 1300 connect the output of zero cross detection circuit 1400 and the first end of sampling resistor Rs respectively, the output of the non-linear reference circuit 900 of input termination of average current ring regulating circuit 1000, the output of the input termination average current ring regulating circuit 1000 of reset circuit 1100, three inputs of main drive circuit 1500 connect the output of interrupted delay circuit 1200 respectively, the output of zero passage detection electric current 1400 and the output of reset circuit 1100, the control end of the output termination switching tube Q1 of main drive circuit 1500.

Wherein, first antihunt circuit 100 and the second antihunt circuit 200 can weaken the vibration when controllable silicon dimmer TR1 opens on input current, vibration can cause input current to fluctuate, if its amplitude drops to below the maintenance electric current of controllable silicon dimmer TR1, so controllable silicon dimmer TR1 can be turned off by mistake.

Leadage circuit 300 is for compensating the maintenance electric current of controllable silicon dimmer TR1 at dimming cycle.In other words, leadage circuit 300 provides the maintenance electric current of controllable silicon dimmer TR1, prevents controllable silicon dimmer TR1 from being turned off by mistake.

First antihunt circuit 100, second antihunt circuit 200 and leadage circuit 300 are all optional.In addition, the position of the first antihunt circuit 100 is in parallel with the output of rectifier bridge after also can adjusting to rectifier bridge, does not affect the function of circuit.

The sinusoidal signal of cut, for detecting the angle of flow after controllable silicon dimmer TR1, is converted to square-wave signal by light modulation phase detecting circuit 600.The square-wave signal that light modulation phase detecting circuit 600 produces is filtered into direct current average voltage by phase filtering circuit 700.The size of the direct current average voltage that non-linear reference circuit 900 exports according to phase filtering circuit 700 produces corresponding reference voltage, and this reference voltage raises with the rising of direct current average voltage.Zero cross detection circuit 1400 detects the current zero-crossing point of output diode and the ON time of output diode directly or indirectly.Output current analog circuit 1300 is according to the sampled voltage analog output current on the Output rusults of this zero cross detection circuit 1400 and sampling resistor Rs.The output signal of the reference voltage that average current ring regulating circuit 1000 exports according to non-linear reference circuit 900 and output current analog circuit 1400 produces adjustment voltage signal.The size of the adjustment voltage that reset circuit 1100 exports according to average current ring regulating circuit 1000 produces switching tube ON time.Interrupted delay circuit 1200 is according to the size adjustment interrupting time of this direct current average voltage, and this interrupting time shortens along with the rising of direct current average voltage.Main drive circuit 1500 produces control signal according to switching tube ON time and interrupting time, and this control signal is used for the turn-on and turn-off of control switch pipe Q1.

Wherein, interrupted delay circuit is only work when LED drive circuit is configured with controllable silicon dimmer TR1, also namely when being configured with controllable silicon dimmer TR1, system operating mode comprises critical continuous mode and interrupted two kinds of patterns, and when not being configured with controllable silicon dimmer TR1, system is operated in critical continuous conduction mode.

The detailed circuit diagram of the first example of this LED drive circuit is shown with reference to figure 3, Fig. 3.

Wherein, the first antihunt circuit 100 comprises: resistance R1 and electric capacity C1.The first end of resistance R1 is connected to the output of controllable silicon dimmer TR1, and the other end of resistance R1 is connected to the first end of electric capacity C1, second output of the second termination alternating current source AC of electric capacity C1.

Second antihunt circuit 200 comprises: resistance R2, resistance R3, resistance R4, electric capacity C2, triode Q2, diode D1, voltage-stabiliser tube Z1 and switching tube Q3.The first end of resistance R2 is connected to first output of rectifier bridge B1, second end of resistance R2 is connected to the first end of resistance R3, second end of resistance R3 is connected to second output of rectifier bridge B1, the anode of diode D1 is connected to the first end of resistance R3, the negative electrode of diode D1 connects the first end of electric capacity C2, second end of electric capacity C2 is connected to second output of rectifier bridge B1, and the negative electrode of voltage-stabiliser tube Z1 is connected to the first end of electric capacity C2, and the anode of voltage-stabiliser tube Z1 is connected to second end of electric capacity C2.The ground level of triode Q2 is connected to the anode of diode D1, and the emitting stage of triode Q2 is connected to the negative electrode of diode D1, and the current collection level of triode Q2 is connected to second end of electric capacity C2.The control end of switching tube Q3 is connected to the first end of electric capacity C2, the first end ground connection of switching tube Q3, second end of the second termination capacitor C2 of switching tube Q3.Resistance R4 is connected in parallel between the first end of switching tube Q3 and the second end.This circuit can regulate controllable silicon dimmer TR1 copped wave overshoot size of current by the size of regulating resistance R4.

Leadage circuit 300 comprises switching tube Q10, resistance R5, resistance R6 and resistance R18.First output of the first termination rectifier bridge B1 of resistance R5, second end of the first input end connecting resistance R5 of switching tube Q10, the first end of the control end connecting resistance R18 of switching tube Q10, the output of the second termination dummy load drive circuit 800 of resistance R18, the first end of the 3rd terminating resistor R5 of switching tube Q10, second output of the second termination rectifier bridge B1 of resistance R5.This circuit can control to flow through dummy load size of current by the size of regulating resistance R5 or resistance R18.

Input filter circuit 400 comprises diode D3 and electric capacity C3.The anode of diode D3 connects first output of rectifier bridge B1, and the negative electrode of diode D3 connects the first end of electric capacity C3, second output of the second termination rectifier bridge B1 of electric capacity C3.

As the optional scheme of one, input filter circuit 400 can also be structure shown in Fig. 4 a, comprising: diode D3, diode Dn1, diode Dn2, diode Dn3, electric capacity C3 and electric capacity Cn1.Wherein, the anode of diode D3 connects first output of rectifier bridge B1, the negative electrode of diode D3 connects the first end of electric capacity C3, second end of electric capacity C3 connects the negative electrode of diode Dn1, the negative electrode of diode Dn1 connects the anode of diode Dn2, and the negative electrode of diode Dn2 connects the anode of diode Dn3, and the negative electrode of diode Dn3 connects the first end of electric capacity C3, the first end of electric capacity Cn1 connects the anode of diode Dn3, and second end of electric capacity Cn1 connects the negative electrode of diode Dn1.

Shown in Fig. 3 and Fig. 4 a, input filter circuit 400 is unidirectional filter structure, electric current can only one-way flow, take the object of this filter structure to be bled off by the electric charge in electric capacity C3 or electric capacity Cn1 when avoiding leadage circuit 300 to work, thus keep the output waveform of input filter circuit 400 not by the impact of leadage circuit 300.

In addition, when some low input or lower powered application scenario can save leadage circuit 300, input filter circuit 400 structure can be structure shown in Fig. 4 b, comprising: electric capacity C3.Wherein, first output of the first termination rectifier bridge B1 of electric capacity C3, second output of the second termination rectifier bridge B1 of electric capacity C3.

LED driver 500 can comprise uptake pathway, transformer T1 and output diode D4.Wherein, uptake pathway is connected in parallel on the winding two ends, former limit of transformer T1, the anode of the termination output diode D4 of the same name of the vice-side winding of transformer T1, second end of the different name termination output capacitance Co of the vice-side winding of transformer T1, the Same Name of Ends of the auxiliary winding of transformer T1 connects the input of zero cross detection circuit 1400, the different name end ground connection of the auxiliary winding of transformer T1, the negative electrode of output diode D4 connects the first end of output capacitance Co.Wherein, uptake pathway can be save in some low power applications occasion.

Light modulation phase detecting circuit 600 comprises potential-divider network, the electric capacity C4 and comparator Uc1 that input resistance R7, R8 are formed.First output of the first termination rectifier bridge B1 of resistance R7, the first end of the second terminating resistor R8 of resistance R7, the second end ground connection of resistance R8, electric capacity C4 is connected in parallel on the two ends of resistance R8, the positive input terminal of comparator Uc1 receives second end of the negative input end connecting resistance R7 of reference voltage V ref, comparator Uc1.This light modulation phase detecting circuit 600 converts the sinusoidal waveform of cut to square by comparator Uc1.

Phase filtering circuit 700 comprises resistance R4 and electric capacity C5, wherein, the first end of resistance R4 connects the output of light modulation phase detecting circuit 600, and second end of resistance R4 connects the first end of electric capacity C5, the second end ground connection of electric capacity C5, this circuit is filtered into DC waveform square wave.

Dummy load drive circuit 800 comprises sawtooth waveforms maker, comparator Uc4, voltage source V dc1, switching tube Q4 and switching tube Q5.The positive input termination of comparator Uc4 has predeterminated frequency, preset peak, the sawtooth waveforms Vsaw1 (this sawtooth waveforms Vsaw1 is generated by sawtooth waveforms maker) of valley, the negative input end of comparator Uc4 connects the output of phase filtering circuit 700, switching tube Q4 can be NPN triode, switching tube Q5 can be PNP triode, the base stage of the output termination switching tube Q4 of comparator Uc4, the base stage of switching tube Q4 connects the base stage of switching tube Q5, the emitter of switching tube Q4 connects the collector electrode of switching tube Q5, the collector electrode of switching tube Q4 connects the output of voltage source V dc1, the grounded emitter of switching tube Q5.If the sawtooth waveforms Vsaw1 being input to comparator Uc4 anode is higher than comparator Uc4 negative terminal voltage, then the output signal of comparator Uc4 is logic high, if low, contrary, by that analogy.The output signal of dummy load drive circuit 800 is continuous print impulse waveform, and the frequency of this impulse waveform is consistent with the frequency of sawtooth waveforms Vsaw1, and ceiling voltage amplitude is the output voltage of voltage source V dc1, and minimum is zero.

Non-linear reference circuit 900 comprises comparator Uc2, sawtooth waveforms maker, resistance R14 and electric capacity C7.Wherein, the negative terminal of comparator Uc2 receives the sawtooth waveforms Vsaw2 of sawtooth waveforms maker generation, the output of the positive termination phase filtering circuit 700 of comparator Uc2, the first end of the output connecting resistance R14 of comparator Uc2, the first end of the second termination capacitor C7 of resistance R14, the second end ground connection of electric capacity C7.Wherein, the peak of sawtooth waveforms Vsaw2, valley and frequency are all default values.When the positive terminal voltage of comparator Uc2 is higher than sawtooth waveforms Vsaw2, it exports as logic high, if lower than sawtooth waveforms Vsaw2, otherwise then, now the output of comparator Uc2 is square wave, then by being a DC voltage waveform after resistance R14, electric capacity C7 filtering.If the positive terminal voltage of comparator Uc2 is all the time higher than sawtooth waveforms Vsaw2 peak value, the now output of comparator Uc2 is the voltage of overall height, so along with the change from low to high of the positive terminal voltage of comparator Uc2, and the linear voltage waveform of output voltage performance for there being high clamper.

Average current ring regulating circuit 1000 comprises operational amplifier A 2, resistance R15 and electric capacity C8.Wherein, the output of the non-linear reference circuit 900 of positive input termination of operational amplifier A 2, the first end of the negative input end connecting resistance R15 of operational amplifier A 2, the output of the second termination output current analog circuit 1300 of resistance R15, the first end of the first end connecting resistance R15 of electric capacity C8, the output of the second termination operational amplifier A 2 of electric capacity C8.This operational amplifier A 2 can be voltage-type or current mode (transconductance type).

Reset circuit 1100 comprises comparator Uc6, current source Ic2, electric capacity C9 and switching tube Q7.Wherein, the output of the negative input termination average current ring regulating circuit 1000 of comparator Uc6, the output of the positive input termination current source Ic2 of comparator Uc6, the other end ground connection of current source Ic, electric capacity C9 is connected in parallel on the two ends of current source Ic2, the first end of switching tube Q7 and the second end are connected in parallel on the two ends of electric capacity C9, the reversed-phase output of rest-set flip-flop Ua2 in the main drive circuit 1500 of control termination of switching tube Q7.

Interrupted delay circuit 1200 comprises resistance R10, resistance R11, resistance R12, resistance R13, electric capacity C6, switching tube Q6, reference voltage source Vref2, current source Ic1, operational amplifier A 1 and comparator Uc6.Wherein, the first end of resistance R10 connects the output of phase filtering circuit 700, the negative input end of the second end concatenation operation amplifier A1 of resistance R10, the negative input end of the first end concatenation operation amplifier A1 of resistance R11, the output of the second end concatenation operation amplifier A1 of resistance R11, the first end of resistance R12 connects the output of reference voltage source Vref2, the positive input terminal of the second end concatenation operation amplifier A1 of resistance R12, the positive input terminal of the first end concatenation operation amplifier A1 of resistance R13, the second end ground connection of resistance R13, the negative input end of the output termination comparator Uc6 of operational amplifier A 1, the first end of current source Ic1 connects the positive input terminal of comparator Uc6, the second end ground connection of current source Ic1, electric capacity C6 is connected in parallel on the two ends of current source Ic1, the first end of switching tube Q6, second end is connected in parallel on the two ends of electric capacity C6, the control end of switching tube Q6 connects the TOFF2 signal of negate operational amplifier A 1 can be differential amplifier, its output is a direct voltage, after the voltage zero-cross of auxiliary winding, current source Ic1 starts to charge to electric capacity C6, the tie point waveform of the anode of switching tube Q6 and current source Ic1 control capacitance C6 and comparator Uc6 is the triangular wave that a slope is fixed, when the voltage of this triangular wave has exceeded the negative terminal direct voltage of comparator Uc6, the output of comparator Uc6 is high level, now main driving pulse is high level, the voltage at electric capacity C6 two ends is by switching tube Q6 short circuit dischange simultaneously, the rest may be inferred, show that output waveform is the square wave of a pulse type.

Output current analog circuit 1300 comprises resistance R16, switching tube Q8, switching tube Q9 and electric capacity C10.Wherein, the first end of switching tube Q8 connects the first end of sampling resistor Rs, second end of switching tube Q8 connects the first end of electric capacity C10, the control end of the control end connecting valve pipe Q9 of switching tube Q8, the second end ground connection of electric capacity C10, the first end of electric capacity C10 connects the first end of R16, the first end of the second end connecting valve pipe Q9 of resistance R16, the second end ground connection of switching tube Q9, the control end of switching tube Q9 connects the TOFF1 signal of negate

Zero cross detection circuit 1400 can comprise comparator Uc7.The positive input terminal ground connection of comparator Uc7, the output of the auxiliary winding Waux of the negative input termination transformer T1 of comparator Uc7.When the voltage at the auxiliary winding Waux two ends of transformer T1 is zero, the output voltage of zero cross detection circuit 1400 is high level.

Main drive circuit 1500 can comprise and door Ua1, rest-set flip-flop Ua2, voltage source V dc2, triode Q11 and triode Q12.The output connecing interrupted delay circuit 1200 output and zero cross detection circuit 1400 is respectively inputted with two of door Ua1, the set input S of rest-set flip-flop Ua2 is met with the output of door, the RESET input R of rest-set flip-flop Ua2 connects the output of reset circuit 1100, first of rest-set flip-flop Ua2 exports the base stage of termination switching tube Q11, switching tube Q11 can be NPN triode, switching tube Q12 can be PNP triode, both form totem pillar drive circuit, the base stage of switching tube Q11 connects the base stage of Q12, the emitter of switching tube Q11 connects the collector electrode of switching tube Q12, the collector electrode of switching tube Q11 connects the output of voltage source V dc2, the grounded emitter of switching tube Q12.The output signal of rest-set flip-flop Ua2 is the waveform of pulse type, by totem pillar drive circuit, driving force is amplified, is urged to the control end of switching tube Q1.

Rest-set flip-flop Ua3 is used for obtaining time signal TOFF1 under off state lower critical conduction mode and negate signal thereof the RESET input R of rest-set flip-flop Ua3 connects the output of zero cross detection circuit 1400, and the set input S of rest-set flip-flop Ua3 connects the output of reset circuit 1100.The positive output end Q output time signal TOFF1 of rest-set flip-flop Ua3, the reversed-phase output of rest-set flip-flop Ua3 the negate signal of output time signal TOFF1

Rest-set flip-flop Ua4 is used for obtaining the ON time signal TOFF2 under off state under discontinuous mode and negate signal thereof the RESET input of rest-set flip-flop Ua3 meets the output Q of rest-set flip-flop Ua2, the set input of rest-set flip-flop Ua4 connects the output of zero cross detection circuit 1400, the positive output end Q output time signal TOFF2 of rest-set flip-flop Ua4, the reversed-phase output of rest-set flip-flop Ua4 the negate signal of output time signal TOFF2

The working signal waveform of circuit diagram shown in Fig. 3 is shown with reference to figure 5, Fig. 5.

Composition graphs 3 and Fig. 5, in Fig. 5, Vbus is the voltage oscillogram that rectifier bridge B1 exports, Cout is the output voltage of light modulation phase detecting circuit 600, Vavg is the output voltage of phase filtering circuit 700, Vdrive is the output voltage of main drive circuit 1500, Vdelay is the output voltage of interrupted delay circuit 1200, Vaux is the output voltage of the auxiliary winding Waux of transformer T1 in LED drive circuit, Vr is the output voltage of non-linear reference circuit 900, and Vbled is the output voltage of dummy load drive circuit 800.

Can find out according to Fig. 5, after the first antihunt circuit 100, second antihunt circuit 200 and leadage circuit 300, the output voltage Vbus of rectifier bridge B1 is the DC voltage waveform of a cut, after light modulation phase detecting circuit 600, the direct voltage Vbus of cut is converted to square wave Cout, again after phase filtering circuit 700, square wave Cout becomes a DC voltage waveform Vavg, dummy load drive circuit 800 compares the voltage of two input by comparator Uc4, the square wave Vbled that output frequency is fixing, and peak value equals Vdc1, square wave Vbled is transferred to the control end of the switching tube Q10 of leakage current circuit 300, due to dynatron performance, emitter voltage equals Vdc1-Vbe, the maximum current flowing through resistance R6 is (Vdc1-Vbe)/R6, and wherein R5 shares a part of voltage to prevent triode Q10 loss excessive, if not the positive terminal voltage of comparator Uc2 of linear reference circuit 900 is higher than negative terminal sawtooth voltage Vsaw2, export as high level, if lower than, otherwise then, now the output of comparator Uc2 is square wave, again by being a DC voltage waveform after resistance R14 and electric capacity C7 filtering, if comparator Uc2 anode input voltage is all the time higher than sawtooth voltage Vsaw2, now comparator Uc2 exports the voltage for overall height, so along with the change from low to high of the positive terminal voltage of comparator Uc2, the linear voltage waveform of output voltage performance for there being high clamper, operational amplifier A 1 in interrupted delay circuit 1200 can be differential amplifier, its output is a direct voltage, after the voltage zero-cross of the auxiliary winding Waux of transformer T1, current source Ic1 starts to charge to electric capacity C6, the positive input terminal of the comparator Uc5 that electric capacity C6 connects is the triangular wave that a slope is fixed, when triangle wave voltage has exceeded the direct voltage amplitude of the negative terminal of comparator Uc5, comparator Uc5 exports as high level, now main driving pulse is high level, the voltage of electric capacity C6 is by switch Q6 short circuit dischange simultaneously, the rest may be inferred, show that the output waveform Vdelay of comparator Uc5 is the square wave of a pulse type, carry out the Continuity signal of control switch pipe Q1.

The detailed circuit diagram of the second example of this LED driver is shown with reference to figure 6, Fig. 6.

Unique difference of Fig. 6 and Fig. 3 is that the circuit structure of LED driver 500 is different, the LED driver 500 of Fig. 6 comprises inductance L 1 and diode D4, the output of the first termination input filter circuit 400 of inductance L 1, the first end of the second termination switching tube Q1 of inductance L 1, the negative electrode of diode D4 connects the second end of inductance L 1, the anode of diode D4 connects the first end of output capacitance Co, the first end of the second termination inductance L 1 of output capacitance Co.

Generally, circuit shown in Fig. 6 is that non-isolation type exports, and circuit shown in Fig. 3 is isolated form output.

The detailed circuit diagram of the 3rd example of this LED driver is shown with reference to figure 7, Fig. 7.

The difference of Fig. 7 and Fig. 3 is that the circuit structure of LED driver 500 is different with the circuit structure of output current analog circuit 1300.

The LED driver of Fig. 7 comprises inductance L 1 and diode D4, the output of the first termination input filter circuit 400 of L1, the first end of the second termination output capacitance Co of inductance L 1, the negative electrode of diode D4 connects the first end of inductance L 1, and the anode of diode D4 connects second end of output capacitance Co.

The output current analog circuit 1300 of Fig. 7 comprises resistance R16, resistance R17, switching tube Q8, switching tube Q9 and electric capacity C10.The first end of switching tube Q8 connects the first end of sampling resistor Rs, and second end of switching tube Q8 connects the first end of electric capacity C10, and the control end of switching tube Q8 connects the TOFF1 signal of negate the second end ground connection of electric capacity C10, the first end of the first end contact resistance R16 of electric capacity C10, the first end of the second end connecting valve pipe Q9 of resistance R16, the first end of the second end contact resistance R17 of switching tube Q9, the second end ground connection of resistance R17, the control end Received signal strength TOFF1 of switching tube Q9.

Although Fig. 6 and Fig. 7 is non-isolation type export structure, inductance L 1 and diode D4 position are also different, and both are different circuit topologies, and performance is also distinguished to some extent.

It should be noted that: the multiple switching tubes mentioned in (1) the application can be the unit switches that bipolar transistor, metal oxide semiconductor field effect tube or multiple bipolar transistor or metal oxide semiconductor field effect tube realize, and be not limited to the concrete type of device that provides in each instantiation; (2) although have employed zero cross detection circuit to realize the Valley-Switching (quasi-resonance control) of the switching tube of LED drive circuit in embodiment in the present invention, but this one only belonging to the switching mode of routine, not core content of the present invention.This professional domain technical staff ought to know and adopts other switching mode as determined frequency continuous current mode and control or fixed discontinuous current mode frequently controlling to be applied to the present invention, basic function of the present invention can be realized equally, thisly should still belong in the protection range of technical solution of the present invention; (3) although what adopt in non-linear reference circuit in the embodiment of the present invention is sawtooth waveforms; this professional domain technical staff ought to know as sawtooth waveforms replaced to exponential wave or other shaped wave; equally also can realize basic function of the present invention, this replacement simply should still belong in the protection range of technical solution of the present invention.

The above is only preferred embodiment of the present invention, not does any pro forma restriction to the present invention.Therefore, every content not departing from technical solution of the present invention, just according to technical spirit of the present invention to any simple amendment made for any of the above embodiments, equivalent conversion, all still belong in the protection range of technical solution of the present invention.

Claims

1. be applicable to a control circuit for the LED drive circuit of controllable silicon dimmer, it is characterized in that, comprising:

2. control circuit according to claim 1, is characterized in that, described light modulation phase detecting circuit comprises:

3. control circuit according to claim 1, is characterized in that, described phase filtering circuit comprises:

4. control circuit according to claim 1, is characterized in that, described non-linear reference circuit comprises:

5. control circuit according to claim 1, is characterized in that, described non-linear reference circuit comprises:

6. control circuit according to claim 1, is characterized in that, described zero cross detection circuit comprises:

3rd comparator, its first input end ground connection, its second input is coupled with the output of described LED drive circuit directly or indirectly, and its output is as the output of described zero cross detection circuit.

7. control circuit according to claim 1, is characterized in that, described output current analog circuit comprises:

8. control circuit according to claim 1, is characterized in that, described output current analog circuit comprises:

9. control circuit according to claim 1, is characterized in that, described average current ring regulating circuit comprises:

10. control circuit according to claim 1, is characterized in that, described reset circuit comprises:

11. control circuits according to claim 1, is characterized in that, described interrupted delay circuit comprises:

12. control circuits according to claim 1, is characterized in that, described main drive circuit comprises:

13. 1 kinds of LED drive circuits being applicable to controllable silicon dimmer, is characterized in that, comprising:

Control circuit according to any one of claim 1 to 12, its first input end connects the first output of described rectifier bridge;

14. LED drive circuits according to claim 13, it is characterized in that, also comprise: the first antihunt circuit, its first end connects the first input end of described rectifier bridge, its second end connects the second input of described rectifier bridge, and described first antihunt circuit triggers the vibration of the AC input current of moment for limiting described controllable silicon dimmer.

15. LED drive circuits according to claim 14, is characterized in that, described first antihunt circuit comprises:

16. LED drive circuits according to claim 13, it is characterized in that, also comprise: the first antihunt circuit, its first end connects the first output of described rectifier bridge, its second end connects the second output of described rectifier bridge, and described first antihunt circuit triggers the vibration of the AC input current of moment for limiting described controllable silicon dimmer.

17. LED drive circuits according to claim 16, is characterized in that, described first antihunt circuit comprises:

18. LED drive circuits according to claim 13, it is characterized in that, also comprise: the second antihunt circuit, second output of described rectifier bridge is via this second antihunt circuit ground connection, and described second antihunt circuit triggers the peak overshoot of the input current of moment for reducing described controllable silicon dimmer.

19. LED drive circuits according to claim 18, is characterized in that, described second antihunt circuit comprises:

First diode, its anode connects the first end of described 3rd resistance;

20. LED drive circuits according to claim 13, it is characterized in that, also comprise: leadage circuit, the first output of described rectifier bridge is via this leadage circuit ground connection, and described leadage circuit is for compensating the maintenance electric current of described controllable silicon dimmer at dimming cycle.

21. LED drive circuits according to claim 20, it is characterized in that, described control circuit also comprises dummy load drive circuit, size according to the direct current average voltage of described phase filtering circuit generation controls described leadage circuit, described dimmer conduction angle is larger, then described direct current average voltage is higher, then the dummy load electric current that provides of described leadage circuit is less.

22. LED drive circuits according to claim 21, is characterized in that, described leadage circuit comprises:

23. LED drive circuits according to claim 21, is characterized in that, described dummy load drive circuit comprises:

24. LED drive circuits according to claim 13, is characterized in that, described input filter circuit comprises:

3rd diode, its anode connects the first output of described rectifier bridge;

25. LED drive circuits according to claim 13, is characterized in that, described input filter circuit comprises:

3rd diode, its anode connects the first output of described rectifier bridge;

26. LED drive circuits according to claim 13, is characterized in that, described input filter circuit comprises:

3rd electric capacity, its first end connects the first output of described rectifier bridge, its second end ground connection.

27. LED drive circuits according to claim 13, is characterized in that, described LED driver comprises:

28. LED drive circuits according to claim 27, is characterized in that, described LED driver also comprises: uptake pathway, with the former limit winding parallel of described transformer.

29. LED drive circuits according to claim 13, is characterized in that, described LED driver comprises:

30. LED drive circuits according to claim 13, is characterized in that, described LED driver comprises: